Pneumococcal Pneumonia Vaccine Series (PCV20 and PPSV23) in Patients With Chronic Lymphocytic Leukemia Associated Immunodeficiency, PROTECT CLL Trial

Prior treatment

• Subjects who have experienced a severe allergic reaction to prior pneumococcal vaccination.
• Subjects who have received a PCV13 or PCV20 pneumococcal vaccination in the last five years.
  • If they have received PPSV23 in ≥ 1 year and no other pneumococcal vaccine they may be included.
• Current or prior use of immunosuppressive medication within 14 days of cycle one day one, EXCEPT for the following permitted steroids:
  • Intranasal, inhaled, topical steroids, eye drops or local steroid injection (e.g., intra-articular injection);
  • Systemic corticosteroids at physiologic doses =\< 10 mg/day of prednisone or equivalent;
  • Steroids as premedication for hypersensitivity reactions (e.g., computed tomography \[CT\] scan premedication).
• Concurrent illness or condition, which, in the opinion of the treating investigator, would negatively impact the subject's study participation.

Other illness

• Active infection requiring systemic antibiotic therapy.

• NAIVE COHORT: Subjects must have a confirmed diagnosis of chronic lymphocytic leukemia (CLL) or small lymphocytic lymphoma (SLL) (collectively referred to as CLL throughout) according to the 2018 International Workshop on CLL.
• NAIVE COHORT: Male or female subject aged \>= 18 years.
• NAIVE COHORT: Subjects must not have received prior therapy for CLL.
• VENETOCLAX-TREATMENT COHORT: Subjects must have a confirmed diagnosis of chronic lymphocytic leukemia (CLL) or small lymphocytic lymphoma (SLL) (collectively referred to as CLL throughout) according to the 2018 International Workshop on CLL.
• VENETOCLAX-TREATMENT COHORT: Subjects must have received venetoclax (any dose) for at least 12 months with the last dose =\< 12 months prior to registration.